Cation and hydrogen bonding effects on the self-association and luminescence of the dicyanoaurate ion, [Au(CN)2]?
作者:Matthias Stender、Marilyn M. Olmstead、Alan L. Balch、Daniel Rios、Saeed Attar
DOI:10.1039/b310085e
日期:——
The colorless salts [C5H10NH2][AuI(CN)2], [C4H8NH2][AuI(CN)2], [Ph2NNH3][AuI(CN)2]·H2O and [(n-C3H7)4N][AuI(CN)2]·H2O have been prepared by evaporation of aqueous solutions of potassium dicyanoaurate and the chloride salt of the appropriate cation. Hydrogen bonding between the cations and the cyano groups of the anions facilitates the formation of structures with strong aurophilic interactions between the anions. Thus, the [Au(CN)2]â ions self-associate in the three salts [C5H10NH2][AuI(CN)2]
(Auâ¯Au 3.0969(3)
Ã
), [C4H8NH2][AuI(CN)2]
(Au1â¯Au2 3.0795(4)
Ã
), [Ph2NNH3][AuI(CN)2]·H2O (Auâ¯Au 3.0866(4)
Ã
), while in [(n-C3H7)4N][AuI(CN)2]·H2O, which lacks NâH units, the gold ions are widely dispersed. The crystals of [C5H10NH2][AuI(CN)2], [C4H8NH2][AuI(CN)2] and [Ph2NNH3][AuI(CN)2]·H2O each show strong blue luminescence at room temperature, while [(n-C3H7)4N][AuI(CN)2]·H2O is non-luminescent.
通过蒸发含钾二氰金酸盐和适当阳离子的氯化物盐的水溶液,制备了无色盐[C5H10NH2][AuI(CN)2]、[C4H8NH2][AuI(CN)2]、[Ph2NNH3][AuI(CN)2]·H2O和[(n-C3H7)4N][AuI(CN)2]·H2O。阳离子和阴离子的氰基之间的氢键有助于形成具有阴离子间强金-金相互作用的结构。因此,[Au(CN)2]⁻离子在三种盐[C5H10NH2][AuI(CN)2]、[C4H8NH2][AuI(CN)2]、[Ph2NNH3][AuI(CN)2]·H2O中自结合(Au⁻Au分别为3.0969(3)Å、3.0795(4)Å、3.0866(4)Å),而在不含N-H单元的[(n-C3H7)4N][AuI(CN)2]·H2O中,金离子广泛分散。[C5H10NH2][AuI(CN)2]、[C4H8NH2][AuI(CN)2]和[Ph2NNH3][AuI(CN)2]·H2O的晶体在室温下均显示出强烈的蓝色发光,而[(n-C3H7)4N][AuI(CN)2]·H2O则不发光。